Porous hexagonal Mn 5O 8 nanosheets as fast-charging anode materials for lithium-ion batteries

Among various metal oxide nanomaterials, manganese oxides, which can exist in different structures and valence states, are considered highly promising anode materials for lithium-ion batteries (LIBs). However, conventional manganese oxides, such as MnO and MnO₂, face significant challenges during cycling process. Specifically, poor electronic conductivity and large volume changes result in low specific capacity during high current charging and discharging, as well as poor fast-charging performance. This work presents an approach to synthesizing porous hexagonal Mn₅O₈ nanosheets via hydrothermal and annealing methods and applies them as anode materials for LIBs. The Mn₅O₈ nanomaterials exhibit a thin plate morphology, which effectively reduces the distance for ion/electron transmission and mitigates the phenomenon of volume expansion. Additionally, the large pore size of Mn₅O₈ results in abundant interlayer and intralayer defects, which further increase the rate of ion transmission. These unique characteristics enable Mn₅O₈ to demonstrate excellent electrochemical performance (938.7 mAh·g⁻¹ after 100 cycles at 100 mA·g⁻¹) and fast charging performance (675.7 mAh·g⁻¹ after 1000 cycles at 3000 mA·g⁻¹), suggesting that Mn₅O₈ nanosheets have the potential to be an ideal fast-charging anode material for LIBs.